G

50 k

G

1

R

:

+

±

+

±

+

±

40 k

25 k

40 k

40 k

40 k

25 k

Overvoltage

Protection

Overvoltage

Protection

RG

REF

+VS

V-

OUT

V+

-VS

-IN

+IN

G

50 k

G

1

R

:

O

IN

IN

REF

V

G V

V

V

Copyright © 2017, Texas Instruments Incorporated

RG

RG

17

INA828

www.ti.com

SBOS792A – AUGUST 2017 – REVISED JANUARY 2018

Product Folder Links: INA828

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Copyright © 2017–2018, Texas Instruments Incorporated

7.3 Feature Description

7.3.1 Setting the Gain

Figure 52 shows that the gain of the INA828 is set by a single external resistor, RG, connected between the RG

pins (pins 1 and 8).

Figure 52. Simplified Diagram of the INA828 With Gain and Output Equations

The value of RG is selected according to:

(1)

Table 1 lists several commonly-used gains and resistor values. The 50-k

Ω term in Equation 1 comes from the

sum of the two internal 25-kΩ feedback resistors. These on-chip resistors are laser-trimmed to accurate absolute

values. The accuracy and temperature coefficients of these resistors are included in the gain accuracy and drift

specifications of the INA828.

Table 1. Commonly-Used Gains and Resistor Values

DESIRED GAIN

RG (Ω)

NEAREST 1% RG (Ω)

1

NC

NC

2

50 k

49.9 k

5

12.5 k

12.4 k

10

5.556 k

5.49 k

20

2.632 k

2.61 k

50

1.02 k

1.02 k

100

505.1

511

200

251.3

249

500

100.2

100

1000

50.05

49.9